diff --git a/biomes.lua b/biomes.lua
index 11bb74f..4942f50 100644
--- a/biomes.lua
+++ b/biomes.lua
@@ -30,6 +30,10 @@ local c_cobble_fungus = minetest.get_content_id("dfcaverns:cobble_with_floor_fun
 -- Coal Dust
 
 local test_biome_floor = function(area, data, ai, vi, bi, param2_data)
+	if data[bi] ~= c_stone then
+		return
+	end
+	
 	if math.random() < 0.25 then
 		data[bi] = c_dirt
 	else
@@ -48,6 +52,8 @@ end
 local test_biome_ceiling = function(area, data, ai, vi, bi)
 	if subterrane:vertically_consistent_random(vi, area) < 0.002 then
 		subterrane:stalactite(vi, area, data, 6, 20, c_stone, c_stone, c_stone)
+	elseif math.random() < 0.03 then
+		dfcaverns.glow_worm_ceiling(area, data, ai, vi, bi)
 	end
 end
 
diff --git a/glow_worms.lua b/glow_worms.lua
new file mode 100644
index 0000000..ccfc8de
--- /dev/null
+++ b/glow_worms.lua
@@ -0,0 +1,47 @@
+-- internationalization boilerplate
+local MP = minetest.get_modpath(minetest.get_current_modname())
+local S, NS = dofile(MP.."/intllib.lua")
+
+minetest.register_node("dfcaverns:glow_worm", {
+	description = S("Glow Worms"),
+	tiles = {"dfcaverns_glow_worm.png"},
+	inventory_image = "dfcaverns_glow_worm.png",
+	wield_image = "dfcaverns_glow_worm.png",
+	is_ground_content = true,
+	groups = {oddly_breakable_by_hand=3},
+	light_source = 9,
+	paramtype = "light",
+	drawtype = "plantlike",
+	walkable = false,
+	buildable_to = true,
+	visual_scale = 1.0,
+	selection_box = {
+		type = "fixed",
+		fixed = {-0.5, -0.5, -0.5, 0.5, -0.5, 0.5},
+	},
+})
+
+local c_air = minetest.get_content_id("air")
+local c_worm = minetest.get_content_id("dfcaverns:glow_worm")
+
+dfcaverns.glow_worm_ceiling = function(area, data, ai, vi, bi)
+	if data[vi] == c_air and data[bi] == c_air then
+		data[vi] = c_worm
+		data[bi] = c_worm
+		if math.random(2) == 1 then
+			local pos = area:position(vi)
+			pos.y = pos.y-2
+			local bbi = area:indexp(pos)
+			if data[bbi] == c_air then
+				data[bbi] = c_worm
+				if math.random(2) == 1 then
+					pos.y = pos.y-1
+					local bbbi = area:indexp(pos)
+					if data[bbbi] == c_air then
+						data[bbbi] = c_worm
+					end
+				end
+			end
+		end
+	end
+end
\ No newline at end of file
diff --git a/init.lua b/init.lua
index 256e5d9..39ac30f 100644
--- a/init.lua
+++ b/init.lua
@@ -11,6 +11,7 @@ local modpath = minetest.get_modpath(minetest.get_current_modname())
 dofile(modpath.."/config.lua")
 
 dofile(modpath.."/ground_cover.lua")
+dofile(modpath.."/glow_worms.lua")
 
 -- Plants
 dofile(modpath.."/plants.lua") -- general functions
diff --git a/textures/dfcaverns_glow_worm.png b/textures/dfcaverns_glow_worm.png
new file mode 100644
index 0000000..56cbeba
Binary files /dev/null and b/textures/dfcaverns_glow_worm.png differ
diff --git a/textures/license.txt b/textures/license.txt
index 65a68bb..8272b90 100644
--- a/textures/license.txt
+++ b/textures/license.txt
@@ -8,4 +8,5 @@ dftrees_tower_cap 	- derived from default dead coral
 dftrees_tower_cap_gills - from caverealms mushroom gills
 dftrees_cave_wheat	- derived from farming wheat
 dftrees_tunnel_tube	- derived from moretrees palm tree bark
-dfcaverns_fungi - copied from caverealms
\ No newline at end of file
+dfcaverns_fungi - copied from caverealms
+dfcaverns_glow_worm - copied from caverealms
\ No newline at end of file